Pebble smartwatch founder Eric Migicovsky is back with a new venture, Core Devices, and a fresh take on wearable technology: the Index 01 AI smart ring. Priced at an accessible $75 for pre-order, this innovative device is designed not as an "always-on" AI assistant or fitness tracker, but as a dedicated tool for quickly capturing voice notes and reminders with a simple press of a button. It aims to offer a private, subscription-free solution for those seeking an "external memory" for their daily thoughts.
AI Functionality and Privacy
Unlike many emerging AI wearables, the Index 01's artificial intelligence functionality is intentionally limited and privacy-centric. Its speech-to-text and AI models run locally on your smartphone via the open-source Pebble mobile app. Crucially, the ring only records when its side button is pressed and held, preventing surreptitious recordings. This design choice ensures that user data remains on their phone, not in the cloud, reinforcing Migicovsky's commitment to privacy and eliminating the need for recurring subscription fees.
Design, Durability, and Purpose
Crafted from stainless steel, the Index 01 is built for everyday life. It boasts water resistance up to 1 meter, making it suitable for activities like showering, washing hands, doing dishes, or walking in the rain. However, it's not intended for swimming or other prolonged water immersion. Migicovsky emphasizes that the ring is not a fitness tracker or sleep monitor; it doesn't collect health metrics like heart rate, aligning with its singular focus on memory capture.
I’m not trying to build some AI assistant thing. I build things that solve one main problem, and they solve it really well. I think of [the ring] as external memory for my brain…that’s what this is. It’s always with you.
Battery Life and Recording Capabilities
One of the ring's standout features is its impressive battery longevity. Migicovsky claims the battery "lasts for years," with an estimated two years of usage based on his personal experience of recording 10-20 short (3-6 second) thoughts daily. The ring supports a total of 12 to 14 hours of recording time. When the battery eventually depletes, users can conveniently ship the device back to Core Devices for recycling. The Index 01 can store up to five minutes of audio per recording session, which can be saved to the ring and later synced to a smartphone, making it ideal for brief personal notes even when a phone isn't immediately accessible. It supports over 100 languages and includes on-device memory for recordings when out of Bluetooth range.
Software and Customization
The Index 01 integrates seamlessly with the Pebble mobile app, which manages notes and reminders. It also offers optional integration with existing calendaring systems and productivity apps like Notion. A key aspect of its design is its open-source software, which invites community development and customization. Beyond its primary press-and-hold recording function, the ring's button is programmable. Users can assign single or double presses to control music playback, operate a phone's camera shutter, send messages via Beeper (another Migicovsky creation), or implement custom voice actions through MCP.
A New Approach to Hardware Development
Migicovsky openly discusses the challenges of hardware development, referencing Pebble's previous acquisition by Fitbit (which Google later acquired). "I didn’t earn any money during Pebble – we exited, but it was not a great exit," he admitted to TechCrunch. However, the open-sourcing of PebbleOS by Google reignited his passion, leading to the creation of Core Devices. This new company, a small, self-funded team of five, is committed to a different, more sustainable business model. "What I’m doing now is trying an alternative path, which is [to] start from profitability," he explained, emphasizing a focus on long-term viability over rapid venture-backed growth.
Core Devices has already successfully launched the Pebble 2 Duo smartwatch, which quickly sold out, and is preparing to ship the upgraded Pebble Time 2, a color e-ink smartwatch with 25,000 pre-orders.
Market Position and Availability
The Index 01 enters a growing market for voice-note wearables, including competitors like Sandbar's Stream Ring, which features a subscription model and a higher price point. The Index 01 is currently available for pre-order at $75 until March 2026, after which its price will increase to $99. It comes in silver, polished gold, and matte black, supporting both iOS and Android devices, with customers able to choose from eight ring sizes (6 to 13).
